A protected grey nurse shark has been killed and dumped on the Stockton breakwall.
The 1.8 metre shark's fins had all been cut off.
The gruesome discovery was made at around 7:30am Thursday.
NSW Fisheries have removed the carcass and will carry out an autopsy.
It's understood a fisherman was caught red-handed by officers on the breakwall, with a bag full of shark fins.
Grey nurse sharks are critically endangered, with about 1000 individuals thought to remain along Australia's east coast.
$2,500 on the spot fines apply for harming, buying, selling or possessing a grey nurse shark with maximum penalties of $220,000.